<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/html">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta content="width=device-width, initial-scale=1.0" name="viewport">
    <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.13/vue.common.dev.js"></script>
</head>
<body>
<div id="app">

</div>
<script>
    const vm = new Vue({
        el: "#app",
        data() {
            return {}
        },
        methods: {},
        mounted() {
            new Promise(resolve => {
                console.log("Promise")
                resolve()
            }).then(() => {
                console.log(123)
            })
            setTimeout(() => {
                console.log(456)
            })
            nextTick(() => {
                console.log("nextTick")
            })
        }
    })
</script>
</body>
</html>